DMAMUX peripheral is a dma request router/trigger, present on g0, wb, h7 and l4+.
Basically it allows to easily map peripheral requests to whatever dma channel we
want to use (similarily to the DMA_CSELR register, but without limitation) but,
it also also adds some clever dma request synchronization and even some dma request
generation logic via internal request generator "channels", allowing some requests
chaining, or triggering reqs from non dma capable peripherals.
nb: g0 only features 1 dmamux bloc, supports 7 irq and 4 generators, l4+ supports 13
dma channels and 3 generators and h7 has two dmamuxes, with support for the 15 dma
channels and 7 generators - so as much CxCR and RGxCR register - but they are bit
to bit compatible - excluding of course the sync/sig and dma requests id mappings.
btw, currently, request generator channels are defined in common header, but maybe
we should define them in device header ? or we dont care (like for dma channels,
only defined in dma_f24 but not for other devices ?).
See ST AN5224 for more information
same same, bit for bit, except not ;) - Channel request mapping now
depends on a new DMAMUX peripheral, and there's no default preset.
So, before enabling dma channel after its configuration, request
must be configured by :
dmamux_set_dma_channel_request(DMAMUX1, DMA_CHANNELx, request_number_from_datasheet);
Add basically what's needed to have some minimal but usefull subset of
function for a timer: irqs, compare, period, out polarity, enable/disable
and start.
Regular rng peripheral, with one additional bit : clock error detection
apparently available on l4 chips). Curiously, Clock error detection is
_disabled_ when bit is set, but bit is cleared by default, so peripheral
/ clock error detection behaves like all other chips..
NB: RNG need proper rcc_ccicr_rngsel bits set to work, no clock is set by
default. Note also that on that chip fRNGCLK must be higher than fHCLK/32
doxygen really wants the @defgroup _and_ the @addtogroup to both have
the full name, matching identically, to avoid all warnings.
Standardize on the "CAPS_PERIPH peripheral API" style.
The leading - makes it rather inconsistent with the majority of other
projects around the world. Use the form everyone else uses.
To solve this, properly pass prefix to inner makes as was always
intended.
Fixes: https://github.com/libopencm3/libopencm3/issues/1058
FLASH_CR_OPTSTRT needs to be written to FLASH_CR, and there is no reason
to mask the last two data bits.
Signed-off-by: Bruno Randolf <br1@einfach.org>
Reviewed-by: Karl Palsson <karlp@tweak.net.au>
(original code appeared to be badly copied from the flash_common_f24 codebase)
